Route searching system, route searching method, and computer program

ABSTRACT

A route searching system, a route searching method, and computer program are provided that enable selection of an appropriate recommended route for a user in consideration of interruption of automated driving control. The route searching system is configured to: when a recommended route from a departure point to a destination including an automated driving section where automated driving control of a vehicle is performed is searched for, acquire a plurality of candidate routes as candidates for the recommended route (S 4 ); for each candidate route, specify an interruption section where the automated driving control is interrupted in the automated driving section in the candidate route (S 8 , S 9 ); based on the interruption section, for each candidate route, acquire interruption information indicating that the automated driving control is interrupted in the automated driving section in the candidate route (S 10 ); and, based on the interruption information, select the recommended route from the candidate routes (S 12 ).

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a National Stage of International Application No.PCT/JP2015/051023, filed on Jan. 16, 2015, which claims priority fromJapanese Patent Application No. 2014-012853, filed on Jan. 27, 2014, thecontents of all of which are incorporated herein by reference in theirentirety.

TECHNICAL FIELD

The present disclosure relates to a route searching system, a routesearching method, and a computer program for searching for a recommendedroute including an automated driving section where automated drivingcontrol of a vehicle is performed.

BACKGROUND ART

In recent years, there are many vehicles equipped with navigationdevices configured to provide travel guidance of the vehicles fordrivers to be able to easily reach desired destinations. Herein, such anavigation device is a device that can detect the current position of avehicle equipped therewith by a GPS receiver, for example, and canacquire map data corresponding to the current position from a recordingmedium such as a DVD-ROM or a HDD or through a network to display themap data on a liquid crystal monitor. Furthermore, this navigationdevice has a route search function of searching for a recommended routefrom the current vehicle position to a desired destination when thedesired destination is input. The navigation device sets a recommendedroute thus found as a guidance route, displays the guidance route on adisplay screen, and also provides audio guidance when, for example, thevehicle approaches an intersection, thereby reliably guiding a user tothe desired destination. In recent years, some of mobile phones, smartphones, tablet terminals, and personal computers, for example, have thesame functions as that of the navigation device.

In recent years, as a traveling mode of a vehicle, other than manualtraveling in which a vehicle travels based on driving operation of auser, traveling by automated driving control has been newly proposedthat causes the vehicle to travel in an automated way along a presetroute without driving operation of the user. In the automated drivingcontrol, for example, the current position of the vehicle, the lane inwhich the vehicle is traveling, and the positions of other vehiclesthere around are detected at any time, and vehicle control of thesteering, the drive source, and the brake, for example, is automaticallyperformed such that the vehicle travels along the preset route. Althoughtraveling by the automated driving control can advantageously reduce thedriving burden on a user, there are situations in which road conditionsmake it difficult to cause the vehicle to travel by the automateddriving control. For example, there are situations in which the vehicleneeds to change lanes or merge into another lane in a short section ortravel in bad weather. In such situations, the vehicle needs tointerrupt traveling by the automated driving control and shift to manualdriving.

In view of this, the navigation device described above, for example, isnewly required to search for a recommended route in consideration ofinterruption of the automated driving control described above. Forexample, in order to cause a vehicle to travel by automated drivingcontrol without being interrupted, Patent Document 1 proposes atechnique of classifying a road having low accuracy of the currentposition detected by the GPS as an automated-control inapplicable roadon which the vehicle cannot travel by the automated driving control, andsearching for a route avoiding the automated-control inapplicable road.

RELATED-ART DOCUMENTS Patent Documents

-   [Patent Document 1] Japanese Patent Application Publication No.    2011-118603 (JP 2011-118603 A) (pages 6 to 7, FIG. 4)

SUMMARY

However, in the technique described in Patent Document 1, because aroute is searched for such that roads classified as automated-controlinapplicable roads are not included, the vehicle can travel by theautomated driving control without being interrupted, but situationsoccur in which a very long roundabout route is searched for and anyroute cannot be searched for in some cases.

The present disclosure has been made to solve conventional problemsdescribed above, and an object thereof is to provide a route searchingsystem, a route searching method, and computer program that make itpossible to select an appropriate recommended route for a user inconsideration of interruption of automated driving control.

A first route searching system, a route searching method, and a computerprogram according to the present disclosure for achieving the object area route searching system that searches for a recommended route from adeparture point to a destination including an automated driving sectionwhere automated driving control of a vehicle is performed, a routesearching method for performing route search using the system, and acomputer program that causes the system to perform the respectivefunctions below. Specifically, the system includes: route candidateacquisition code for acquiring a plurality of candidate routes that arecandidates for the recommended route; interruption section specifyingcode for, for each of the candidate routes acquired by the routecandidate acquisition code, specifying an interruption section whereautomated driving control is interrupted in the automated drivingsection included in the candidate route; interruption informationacquisition code for, based on the interruption section specified by theinterruption section specifying code, for each of the candidate routes,acquiring interruption information indicating that the automated drivingcontrol is interrupted in the automated driving section included in thecandidate route; and recommended-route selecting code for selecting therecommended route including the interruption section from among thecandidate routes, based on the interruption information acquired by theinterruption information acquisition code.

A second route searching system, a route searching method, and acomputer program according to the present disclosure are a routesearching system that searches for a recommended route from a departurepoint to a destination including an automated driving section whereautomated driving control of a vehicle is performed, a route searchingmethod for performing route search using the system, and a computerprogram that causes the system to perform the respective functionsbelow. Specifically, the system includes: route candidate acquisitioncode for acquiring a plurality of candidate routes that are candidatesfor the recommended route; interruption-predicted section specifyingcode for, for each of the candidate routes acquired by the routecandidate acquisition code, specifying an interruption-predicted sectionwhere there is a possibility that automated driving control will beinterrupted in the automated driving section included in the candidateroute; interruption-predicting information acquisition code for, basedon the interruption-predicted section specified by theinterruption-predicted section specifying code, for each of thecandidate routes, acquiring interruption-predicting informationindicating that the automated driving control is predicted to beinterrupted in the automated driving section included in the candidateroute; and recommended-route selecting code for selecting therecommended route including the interruption-predicted section fromamong the candidate routes, based on the interruption-predictinginformation acquired by the interruption-predicting informationacquisition code.

With the first route searching system, the route searching method, andthe computer program according to the present disclosure having thestructure described above, when a route to a destination is searchedfor, a recommended route can be selected in consideration of aninterruption section where automated driving control is interrupted. Byusing interruption information on interruption of the automated drivingcontrol, while preventing the occurrence of a situation in which anexcessively long roundabout route is found or no route is found, it ispossible to select a more appropriate recommended route for the user.

With the second route searching system, the route searching method, andthe computer program according to the second aspect of the presentdisclosure, when a route to a destination is searched for, a recommendedroute can be selected in consideration of an interruption-predictedsection where there is a possibility that the automated driving controlwill be interrupted. By using interruption-predicting information oninterruption prediction of the automated driving control, whilepreventing the occurrence of a situation in which an excessively longroundabout route is found or no route is found, it is possible to selecta more appropriate recommended route for the user.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a structure of a navigationdevice according to a first embodiment.

FIG. 2 is a flowchart of a route-search processing program according tothe first embodiment.

FIG. 3 is a figure illustrating an example of correspondence betweenadditional values α and reasons for the interruption of automateddriving control.

FIG. 4 is a diagram illustrating a route guidance screen providingguidance for a recommended route displayed on a liquid crystal display.

FIG. 5 is a diagram illustrating the route guidance screen providingguidance for a candidate route other than the recommended routedisplayed on the liquid crystal display.

FIG. 6 is a diagram illustrating an example of control contents of theautomated driving control that are set for a planned traveling route ofa vehicle.

FIG. 7 is a flowchart of a sub-processing program ofinterruption-section coupling processing.

FIG. 8 is an explanatory diagram for explaining coupling of interruptionsections.

FIG. 9 is a flowchart of an automated-driving-control processing programaccording to the first embodiment.

FIG. 10 is a flowchart of a sub-processing program ofinterruption-section detection processing.

FIG. 11 is a figure illustrating an example of correspondence betweenadditional values α and probabilities that the automated driving controlwill be interrupted.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A route searching system according to the present disclosure will now bedescribed with reference to the drawings on the basis of a firstembodiment and a second embodiment implemented in a navigation device.

First Embodiment

Referring to FIG. 1, a schematic structure of a navigation device 1according to the first embodiment will be described first. FIG. 1 is ablock diagram illustrating the navigation device 1 according to thefirst embodiment.

As depicted in FIG. 1, the navigation device 1 according to the firstembodiment includes: a current-position detecting unit 11 that detectsthe current position of a vehicle equipped with the navigation device 1;a data recording unit 12 in which various types of data are recorded; anavigation electronic control unit (ECU) 13 that performs various typesof arithmetic processing on the basis of input information; an operatingunit 14 that receives operation from a user; a liquid crystal display 15that displays a map around the vehicle, information on a route found bya later-described route search processing to the user, and other items;a speaker 16 that outputs audio guidance about route guidance; a DVDdrive 17 that reads a DVD as a recording medium; and a communicationmodule 18 that communicates with information centers such as a probecenter and a Vehicle Information and Communication System (VICS,registered trademark) Center. The navigation device 1 is connected to avehicle exterior camera 19 that is mounted on the vehicle equipped withthe navigation device 1 and various sensors through an in-vehiclenetwork such as a CAN. Furthermore, the navigation device 1 is connectedto a vehicle control ECU 20 that performs various controls on thevehicle equipped with the navigation device 1 in a manner capable ofbidirectional communication. The navigation device 1 is also connectedto various operation buttons 21 installed in the vehicle, such as anautomated driving switch and an automated driving start button describedlater.

The following describes the respective components constituting thenavigation device 1 in order. The current-position detecting unit 11includes a GPS 22, a vehicle speed sensor 23, a steering sensor 24, anda gyroscopic sensor 25, and can detect the current position and theorientation of the vehicle, the traveling speed of the vehicle, and thecurrent time, for example. In particular, the vehicle speed sensor 23,which is a sensor for detecting the travel distance of the vehicle andthe vehicle speed, generates pulses depending on the rotation of drivewheels of the vehicle, and outputs pulse signals to the navigation ECU13. The navigation ECU 13 counts the generated pulses to calculate therotation speed of the drive wheels and the travel distance. Herein, thenavigation device 1 does not have to include all of four types of thesensors described above, and the navigation device 1 may include onlyone or some of these sensors.

The data recording unit 12 includes a hard disk (not depicted) as anexternal storage and a recording medium and a recording head (notdepicted). The recording head is a driver for reading map information DB31 and a predetermined program, for example, stored in the hard disk andwriting predetermined data in the hard disk. Herein, the data recordingunit 12 may include an optical disk such as a memory card, a CD, or aDVD instead of the hard disk. The map information DB 31 may be stored inan external server, and the navigation device 1 may be configured toacquire the map information DB 31 through communication.

The map information DB 31 is a storage device for storing, for example,link data 33 on roads (links), node data 34 on node points, search data35 used for processing related to search and change of a route, facilitydata on facilities, map display data for displaying a map, intersectiondata on respective intersections, and search data for searching forlocations.

Examples of data each recorded as the link data 33 include: data on therespective links constituting roads representing widths, slopes, cants,and banks of the roads, conditions of road surfaces, merging sections,the number of lanes of the roads, locations where the number of lanesdecreases, locations where the roads narrow, and railroad crossings, forexample; data on corners representing curvature radii, intersections,T-junctions, and entrances and exits of the corners, for example; dataon road attributes representing downhill roads and uphill roads, forexample; data on road types representing ordinary roads such as anational highway, a prefectural road, and a narrow street and toll roadssuch as a national expressway, an urban expressway, a motor highway, anordinary toll road, and a toll bridge, for example.

As the node data 34, for example, pieces of data are recorded thatrelate to: coordinates (locations) of a node point set for each actualroad junction (including an intersection and a T-junction) and set foreach road at each distance determined based on curvature radii, forexample; a node attribute representing whether the node is a nodecorresponding to an intersection; a connection link number list that isa list of link numbers of links connected to the node; an adjacent nodenumber list that is a list of node numbers of the nodes adjacent to thenode through the links; and data regarding the height (altitude) andother properties of each node, for example.

As the search data 35, various types of data are recorded that are usedfor route search processing in which a route from a departure point(e.g., the current position of the vehicle) to a destination is searchedfor as described later. Specifically, cost calculation data is storedthat is used for calculating a search cost. The search cost means a costrepresenting the numerical level of appropriateness of an intersectionas part of a route (hereinafter, called “intersection cost”) and a costrepresenting the numerical level of appropriateness of a link in a roadas part of a route (hereinafter, called “link cost”), for example. Notethat, in the first embodiment, a recommended route is searched for byusing a required time from the departure point to the destination asdescribed later, and therefore various types of data for calculating arequired time for the route is also stored in the search data 35.Herein, the search cost may be defined by the required time.

In the navigation device 1 according to the first embodiment,particularly when a recommended route from the departure point to thedestination including an automated driving section where automateddriving control of the vehicle is performed is searched for, therecommended route is searched for based on interruption informationindicating that the automated driving control is interrupted in theautomated driving section. Specifically, when an interruption sectionwhere the automated driving control is interrupted is included,additional values corresponding to the numbers of times, durations,distances, and locations of the interruption of the automated drivingcontrol and the reasons for the interruption are added to the requiredtimes described above, and the resulting required times containing theadditional values are compared to each other, whereby the recommendedroute is searched for.

As a traveling mode of the vehicle, in addition to traveling by manualdriving in which the vehicle travels based on driving operation of theuser, traveling by the automated driving control is available thatcauses the vehicle to travel in an automated way along a preset routewithout driving operation of the user. In the automated driving control,for example, the current position of the vehicle, the lane in which thevehicle is traveling, and the positions of other vehicles therearoundare detected at any time, and vehicle control of the steering, the drivesource, and the brake, for example, is automatically performed by thevehicle control ECU 20 such that the vehicle travels along the routepreset. Details of the automated driving control are already publiclyknown, and thus description thereof is omitted. The automated drivingcontrol may be performed in all road sections. However, the followingdescription is made assuming that, as an automated driving section wherethe automated driving control of the vehicle is performed, an expresswayis set that is provided with gates (it does not matter whether the gateis manned or unmanned, or whether it is toll-free or charged) atboundaries between the expressway and other roads connected thereto, andthe automated driving control is basically performed only when thevehicle is traveling in the automated driving section. Note that anothersection may be set as the automated driving section. For example, anational expressway, an urban expressway, a motor highway, a toll road,and an ordinary road may be set as the automated driving section. Whenthe vehicle travels in the automated driving section, the automateddriving control is not always performed, and the automated drivingcontrol is selected to be performed by the user and is performed only insituations appropriate for the vehicle to travel by the automateddriving control as described later. In other words, the automateddriving section is a section where the vehicle is allowed to perform theautomated driving control in addition to the manual driving.

Although traveling by the automated driving control can advantageouslyreduce the driving burden on the user, there are situations in whichroad conditions make it difficult to cause the vehicle to travel by theautomated driving control. In the navigation device 1 according to thefirst embodiment, sections where such situations occur in which it isdifficult for the vehicle to perform the automated driving control inthe automated driving section are set as interruption sections where theautomated driving control of the vehicle is interrupted to cause thevehicle to travel by the manual driving. The setting of the interruptionsections is basically performed during route search, and is alsoperformed when the vehicle is traveling after the route search. Forexample, when a section where lane markings ahead of the vehicle in thetraveling direction are faint is newly detected or a section where theweather has quickly become worse is newly detected, it is difficult toperform the automated driving control in this section, and thus thissection is newly set as an interruption section. Details of the settingof the interruption sections and route search based on the setinterruption sections are described later.

The navigation ECU 13, which is an electronic control unit that performsoverall control of the navigation device 1, includes a CPU 41 serving asan arithmetic unit and a control unit, and also includes internalstorages such as: a RAM 42 that is used as a working memory when the CPU41 performs various types of arithmetic processing and that stores routedata, for example, when a route is searched for; a ROM 43 that stores aroute-search processing program (see FIG. 2) and anautomated-driving-control processing program (see FIG. 9) describedlater, for example, in addition to control programs; and a flash memory44 that stores programs read from the ROM 43. The navigation ECU 13configures various types of code as processing algorithms. For example,the route candidate acquisition code acquires a plurality of candidateroutes that are candidates for the recommended route. The interruptionsection specifying code, for each of the candidate routes acquired bythe route candidate acquisition code, specifies an interruption sectionwhere the automated driving control is interrupted in the automateddriving section included in the candidate route. The interruptioninformation acquisition code, based on the interruption sectionspecified by the interruption section specifying code, for each of thecandidate routes, acquires interruption information indicating that theautomated driving control is interrupted in the automated drivingsection included in the candidate route. The recommended-route selectingcode selects the recommended route including the interruption sectionfrom among the candidate routes on the basis of the interruptioninformation acquired by the interruption information acquisition code.

The operating unit 14 is operated when a departure point as a travelstart point and a destination as a travel end point are input, forexample, and includes a plurality of operation switches (not depicted)such as various keys and buttons. The navigation ECU 13, based on switchsignals output by depressing the respective switches, for example,performs the various corresponding controls. The operating unit 14 maybe alternatively structured with a touch panel provided on a frontsurface of the liquid crystal display 15. The operating unit 14 may bealso structured with a microphone and a voice recognition device.

The liquid crystal display 15 displays a map image including roads,traffic information, operation guidance, an operation menu, guidance forkeys, candidates for a recommended route from the departure point to thedestination that are found during route search, various types ofinformation on the candidates for the recommended route, guidanceinformation along a guidance route, news, weather forecasts, time, mail,and television programs, for example. Instead of the liquid crystaldisplay 15, a HUD or a HMD may be used.

The speaker 16 outputs audio guidance providing guidance for travelingalong the guidance route based on instructions from the navigation ECU13 and guidance about traffic information.

The DVD drive 17 is a drive that can read data stored in a recordingmedium such as a DVD or a CD. Based on the read data, music or video isreplayed and the map information DB 31 is updated, for example.

The communication module 18 is a communication device for receivingtraffic information, probe information, and weather information, forexample, transmitted from traffic information centers such as a VICScenter and a probe center, and examples of the communication module 18include a mobile phone and a DCM. The examples also include avehicle-to-vehicle communication device that communicates betweenvehicles and a road-to-vehicle communication device that communicatesbetween a roadside unit and a vehicle.

The vehicle exterior camera 19 is structured with a camera using asolid-state image sensing device such as a CCD, and is attached above afront bumper of the vehicle and is disposed with its optical axisdirected downward by a predetermined angle from the horizontal plane.The vehicle exterior camera 19 captures images of a scene ahead of thevehicle in the traveling direction when the vehicle travels in theautomated driving section. The vehicle control ECU 20 detects lanemarkings painted on a road on which the vehicle travels and detectsother vehicles therearound, for example, by performing image processingon the captured images, and performs the automated driving control ofthe vehicle on the basis of the detection result. Meanwhile, thenavigation ECU 13 detects a section (e.g., a section where lane markingsare faint) where a situation occurs in which it is difficult for thevehicle to perform the automated driving control on the basis of thecaptured images captured by the vehicle exterior camera 19 as describedlater when the vehicle travels in the automated driving section. Thesection thus detected is newly set as an interruption section asdescribed later. The vehicle exterior camera 19 may be disposed on therear or the side of the vehicle other than the front thereof. To detecta section where a situation occurs in which it is difficult for thevehicle to travel by the automated driving control, instead of thevehicle exterior camera 19, various sensors such as an illuminancesensor and a rain sensor may be used. In this case, for example, heavyrain or dense fog can be detected. As means for detecting othervehicles, instead of the camera, a sensor such as a millimeter waveradar, vehicle-to-vehicle communication, or road-to-vehiclecommunication may be used.

The vehicle control ECU 20 is an electronic control unit that controlsthe vehicle equipped with the navigation device 1. The vehicle controlECU 20 is connected to various drive units of the vehicle, such as asteering, a brake, and an accelerator. In the first embodiment,particularly when the vehicle travels in the automated driving section,the vehicle control ECU 20 controls the various drive units to performthe automated driving control of the vehicle. The navigation ECU 13transmits an instruction signal related to the automated driving controlto the vehicle control ECU 20 through the CAN at the time when a plannedtraveling route (guidance route) of the vehicle has been determined. Thevehicle control ECU 20 then performs the automated driving control afterthe start of traveling in accordance with the received instructionsignal. The contents of the instruction signal are informationspecifying the planned traveling route (guidance route) and informationon control contents (e.g., going straight, changing lanes to the right,merging) of the automated driving control performed on the vehicle thatare set for sections in the automated driving section included in theplanned traveling route from which interruption sections are excluded.

The following describes the route-search processing program that the CPU41 executes in the navigation device 1 according the first embodimenthaving the structure described above with reference to FIG. 2. FIG. 2 isa flowchart of the route-search processing program according to thefirst embodiment. This route-search processing program, which isexecuted when predetermined operation for performing route search isreceived in the navigation device 1, is a program for searching for arecommended route from a departure point to a destination. Programsillustrated by the flowcharts in FIG. 2, FIG. 7, FIG. 9, and FIG. 10 arestored in the RAM 42 and the ROM 43 included in the navigation device 1,and are executed by the CPU 41.

To begin with, in the route-search processing program, at step(hereinafter, abbreviated as “S”) 1, the CPU 41 determines whether theautomated driving switch is ON. This automated driving switch is aswitch that allows the user to switch between causing the vehicle tobasically perform the automated driving control in the automated drivingsection and causing the vehicle to perform the manual driving withoutperforming the automated driving control, and is disposed on aninstrument panel, for example.

If it is determined that the automated driving switch is ON (YES at S1),the process proceeds to S3. If it is determined that the automateddriving switch is OFF (NO at S1), the process proceeds to S2.

Specifically, when it has been determined that the automated drivingswitch is ON, the user wants the automated driving control to beperformed in the automated driving section. Thus, at and after S3described later, the CPU 41 assumes that the vehicle basically performsthe automated driving control in the automated driving section, andsearches for a recommended route from the departure point to thedestination.

In contrast, when it has been determined that the automated drivingswitch is OFF, the user wants the manual driving to be performed in theautomated driving section without performing the automated drivingcontrol. Thus, at S2, the CPU 41 assumes that the vehicle performs themanual driving in the automated driving section, and searches for arecommended route from the departure point to the destination. Herein,the search processing for a recommended route at S2 is the same asnormal route search processing in which the automated driving control isnot considered, and thus description thereof is omitted. When the routesearch processing is performed, guidance for a recommended route and theother candidate routes other than the recommended route (e.g., routesfound through search with priority on distance, priority on ordinaryroads, and priority on toll roads) is displayed on the liquid crystaldisplay 15. Out of the routes for which guidance is displayed, the userselects a planned traveling route (guidance route) of the vehicle.Subsequently, the navigation device 1 provides guidance for traveling onthe basis of the planned traveling route thus selected.

At S3, the CPU 41 acquires the departure point and the destination. Thedeparture point may be the current position of the vehicle, or may beany location (e.g., home) designated by the user. The destination isacquired based on operation (e.g., operation of searching for orselecting a facility) of the user that the operating unit 14 receives.

Next, at S4, the CPU 41 prepares candidate routes that are candidatesfor the recommended route. The preparation of the candidate routes isperformed by using a known Dijkstra's algorithm. Specifically, the routesearch is performed from the departure point side and also from thedestination side. In the overlapping area between the search from thedeparture point side and the search from the destination side, a costadded value is calculated that is a value obtained by adding up thesearch cost (the node cost and the link cost) accumulated from thedeparture point side, the search cost accumulated from the destinationside, and the toll cost based on tolls required for the travel. The CPU41 specifies a certain number of (e.g., a maximum of five) routes as thecandidate routes in ascending order of the cost added value thuscalculated.

The processing of the following S5 to S11 is performed for eachcandidate route prepared at S4 described above. After the processing ofS5 to S11 is performed for all of the prepared candidate routes, theprocess proceeds to S12.

At S5, the CPU 41 determines whether an automated driving section isincluded in each candidate route to be processed. This automated drivingsection is a section where the automated driving control is basicallyperformed when the vehicle travels in this section as described aboveand, for example, an expressway falls thereunder.

If it is determined that an automated driving section is included in thecandidate route to be processed (YES at S5), the process proceeds to S6.If it is determined that no automated driving section is included in thecandidate route to be processed (NO at S5), the process proceeds to S11.

At S6, the CPU 41 determines whether, about the automated drivingsection included in the candidate route to be processed, there is aninterruption record of the automated driving control recorded when thevehicle traveled in this section in the past. The interruption record ofthe automated driving control includes information specifying thelocation (the start position and the end position of the interruption),the time, and the distance of the interruption of the automated drivingcontrol and the reasons for the interruption. The interruption record ofthe automated driving control may be stored in the data recording unit12, or may be stored in an external server. Furthermore, if theinterruption record is stored in the external server, in addition to theinterruption record of the vehicle, interruption records of othervehicles may be also stored therein.

If it is determined that, about the automated driving section includedin the candidate route to be processed, there is an interruption recordof the automated driving control recorded when the vehicle traveled inthis section in the past (YES at S6), the process proceeds to S7. If itis determined that, about the automated driving section included in thecandidate route to be processed, there is no interruption record of theautomated driving control recorded when the vehicle traveled in thissection in the past (NO at S6), the process proceeds to S8.

At S7, about the automated driving section included in the candidateroute to be processed, the CPU 41 acquires the interruption record ofthe automated driving control recorded when the vehicle traveled in thissection in the past. Specifically, when the interruption record of theautomated driving control is stored in the data recording unit 12, theinterruption record is read out from the data recording unit 12. If theinterruption record of the automated driving control is alternativelystored in the external server, the interruption record is acquired bycommunicating with the external server.

Subsequently, at S8, the CPU 41 specifies a section (hereinafter, called“interruption section”) where the automated driving control isinterrupted in the automated driving section included in the candidateroute. As the interruption section, a section where a situation occursin which it is difficult for the vehicle to perform the automateddriving control is specified base on road shapes, lane markings, trafficinformation, weather information, and interruption records of theautomated driving control in the past, for example. In the interruptionsection, the automated driving control of the vehicle is interrupted,and traveling by the manual driving is performed. For example, a sectionthat falls under any of the conditions (1) to (5) below is specified asan interruption section.

(1) a section where merging or lane change is necessary in a shortdistance (e.g., 500 meters or shorter).

(2) a section where lane markings (e.g., a roadway centerline, a laneboundary, a roadway outside line) disappear or fade to the extent thatthe lane markings cannot be recognized by a camera.

(3) a section where lanes are restricted due to an accident,construction, or a fallen object, for example, and which lane isrestricted cannot be identified.

(4) a section where the weather is so bad (e.g., heavy rain, dense fog,snow cover, icy road) that it is difficult to perform detection with acamera and sensors or it is difficult to perform vehicle control whenthe vehicle travels.

(5) a section where the automated driving control was interrupted in thepast other than the sections that fall under the conditions of (1) to(4).

Whether a section falls under the conditions (1) to (4) is determinedbased on, for example, map information, VICS information, probeinformation, vehicle-to-vehicle communication, and road-to-vehiclecommunication. Whether a section falls under the condition (5) isdetermined based on the interruption record acquired at S7 describedabove. Note that the interruption section specified at S8 describedabove is a temporarily specified one, and is subjected to coupling ofinterruption sections at S9 described later to be finally determined andset as an interruption section. Furthermore, the setting of theinterruption section is basically performed during route search (S8,S9), and is also performed when the vehicle is traveling after the routesearch as described later (S47 in FIG. 10).

Next, at S9, the CPU 41 performs interruption-section couplingprocessing (FIG. 7) described later. The interruption-section couplingprocessing is processing for connecting interruption sections thatsatisfy a certain condition and are adjacently arranged along acandidate route as described later to set one continuous interruptionsection.

Subsequently, at S10, based on the interruption section set at S8 and S9described above, the CPU 41 acquires interruption information indicatingthat the automated driving control is interrupted in the candidate routeto be processed. The interruption information contains the number oftimes, durations, distances, and locations of the interruption of theautomated driving control in the candidate route to be processed and thereasons for the interruption. Herein, the times, the distances, thelocations, and the reasons are acquired for the respective interruptionsections.

Subsequently, at S11, the CPU 41 calculates, for the candidate route tobe processed, a decision value D that is an index for selection of arecommended route. Specifically, the decision value D is calculated by amethod described below.

To begin with, a required time T (minute) necessary for the vehicle totravel in a candidate route is acquired. The required time T iscalculated based on map information, and traffic information, forexample. Next, to the required time T thus calculated, an additionalvalue α based on the interruption information acquired at S10 describedabove is added. The sum of the required time T and the additional valueα is set as a decision value D. The additional value α is calculated byusing at least one or more of the number of times, durations, distances,locations of the interruption of the automated driving control and thereasons for the interruption. For example, any one of or the sum of someof (A) to (C) below is set as the additional value α. (A) two minutesmultiplied by the number of times that the automated driving control isinterrupted on the candidate route, (B) sum (minute) of durations duringwhich the automated driving control is interrupted on the candidateroute, (C) sum (km) of distances for which the automated driving controlis interrupted on the candidate route.

When the additional value α is calculated by using locations where theautomated driving control is interrupted, calculation is made such thatthe additional value α is larger as a location of the interruption iscloser to the destination on the candidate route. For example, the ratioof “the distance from the departure point to the interruption end point”to “the total length of the candidate route” is multiplied by “therequired time×0.1”, and the product is set as the additional value α.When a plurality of interruption sections exist, the additional value αmay be calculated for each of the interruption sections, and thedecision value D may be calculated by using only the largest additionalvalue α, or the decision value D may be calculated by adding all thecalculated additional values α to the required time T.

When the additional value α is calculated by using reasons for theinterruption of the automated driving control, calculation is made suchthat the additional value α is larger as it is more difficult for thevehicle to travel by the automated driving control. Herein, FIG. 3 is afigure illustrating an example of correspondence between additionalvalues α and reasons for the interruption of the automated drivingcontrol. For example, in the case where the candidate route includes asection that is set as an interruption section because merging or lanechange is performed in a short section (e.g., 500 meters or shorter),particularly when the candidate route includes an interruption sectionwhere merging or lane change is performed in a distance longer than 100meters and equal to or shorter than 500 meters, the additional value αis calculated to be “1”. When the candidate route includes aninterruption section where merging or lane change is performed in adistance equal to or shorter than 100 meters, the additional value α iscalculated to be “2”. When the road shape of the interruption sectionwhere merging or lane change is performed cannot be identified from mapinformation, the additional value α is calculated to be “3”. In the casewhere the candidate route includes a section that is set as aninterruption section because of snow cover or an icy road when thevehicle travels, particularly when the candidate route includes aninterruption section for which icy road information exists in VICSinformation, the additional value α is calculated to be “3”. When thecandidate route includes an interruption section for which VICSinformation does not exist but the snowfall probability is highaccording to the weather forecast (e.g., 80% or higher), the additionalvalue α is calculated to be “2”. When the candidate route includes aninterruption section for which VICS information does not exist and thesnowfall probability is low according to the weather forecast (e.g.,lower than 80%), the additional value α is calculated to be “1”. In thesame manner, for other reasons, the additional values are calculated asdepicted in FIG. 3. Herein, when there are a plurality of interruptionsections, the additional value α may be calculated for each of theinterruption sections, and the decision value D may be calculated byusing only the largest additional value α, or the decision value D maybe calculated by adding all the additional values α calculated to therequired time T.

If no automated driving section is included in the candidate route to beprocessed (NO at S5), the required time T (minute) necessary for thevehicle to travel on the candidate route is set to be the decision valueD. After the decision values D are calculated for all of the candidateroutes prepared at S4 described above, the process proceeds to S12.

At S12, the CPU 41 selects a recommended route from among the candidateroutes prepared at S4 described above. Specifically, the CPU 41 comparesthe decision values D of the respective candidate routes and selects,from among the candidate routes, the candidate route having the smallestdecision value D as the recommended route. Herein, the recommended routemay be selected in plurality. Note that, at S12, as a recommended route,the candidate route having the smallest decision value D is selectedregardless of whether an interruption section is included therein. Thus,there are occasions when a candidate route including an interruptionsection is selected as a recommended route, and there are occasions whena candidate route including no interruption section is selected as arecommended route.

Next, at S13, the CPU 41 provides guidance about the respective piecesof information on the recommended route selected at S12 described aboveand the other candidate routes other than the recommended route. Herein,guidance only about the information on the recommended route may beprovided. Alternatively, among the candidate routes other than therecommended route, not all of these routes but only a certain number of(e.g., two in the ascending order of the decision value D) routes may bepicked up as routes the guidance for which is provided. In particular,when an automated driving section is included in the recommended routeor in the other candidate routes, guidance is provided in a mannerdistinguishing a section that corresponds to an interruption sectionfrom a section that does not correspond thereto. In other words,guidance about the section that corresponds to an interruption sectionand guidance about the section that does not correspond thereto areprovided in different guidance manners. Furthermore, when guidance forthe recommended route and the other candidate routes is provided,guidance about the interruption information acquired at S10 describedabove is provided together.

FIG. 4 and FIG. 5 are diagrams illustrating a route guidance screen 51that provides guidance for a recommended route and candidate routesother than the recommended route displayed on the liquid crystal display15 at S13 described above. As depicted in FIG. 4 and FIG. 5, on theroute guidance screen 51, an information window 52 is displayed thatdisplays information on the recommended route and other candidate routesto be guided in a list form for each route. The route that isparticularly selected by a cursor 53 in the information window 52 isdisplayed in a manner superimposed on the map image at the left side ofthe screen. For example, FIG. 4 depicts the route guidance screen 51 inwhich the recommended route 54 is selected, and FIG. 5 depicts the routeguidance screen 51 in which the candidate route 55 other than therecommended route is selected. In the information window 52, informationparticularly containing interruption information is displayed asinformation on the recommended route, for example. Specifically, (a) thenumber of times that the automated driving control is interrupted on theroute, (b) the total distance for which the automated driving control isinterrupted on the route, and (c) the required time are displayed foreach route. Herein, the total duration during which the automateddriving control is interrupted on the route may be displayed. Theinformation window 52 is displayed in a sorted manner, whichspecifically provides guidance for a route with a higher priority in aprioritized manner among the candidate routes. The priorities arebasically set to be higher for a smaller decision value D, but may beset based on the number of times, durations, distances, and locations ofthe interruption of the automated driving control and the reasons forthe interruption. When the recommended route 54 or the candidate route55 displayed in a manner superimposed on the map image at the left sideof the screen includes an automated driving section, the displaying isperformed such that a section that corresponds to the automated drivingsection is distinguished from a section that does not correspondthereto. For example, in the examples depicted in FIG. 4 and FIG. 5, theautomated driving sections are indicated by solid lines, and sectionsother than the automated driving sections are indicated by dashed lines.In particular, for each section corresponding to an interruption sectionin the automated driving section, a section-specifying line segment 56connecting between the start point and the end point of the interruptionsection is displayed so as to distinguish the section from the othersections. Furthermore, near each section-specifying line segment 56, thereason for the interruption of the automated driving control isdisplayed with an interruption icon 57. For example, in the routeguidance screen 51 depicted in FIG. 5, interruption sections exist attwo locations on the candidate route 55, and it is indicated that theinterruption section on the departure point side is set as aninterruption section because of being a section where merging needs tobe performed in a short section. It is also indicated that theinterruption section on the destination side is set as an interruptionsection because of being a section where lanes are restricted due to anaccident, construction, or a fallen object, for example, and which laneis restricted cannot be identified.

By watching the route guidance screen 51 displayed on the liquid crystaldisplay 15, the user can understand the recommended route and thecandidate routes other than the recommended route from the departurepoint to the destination and where and how the automated driving controlis interrupted when traveling on the respective routes (e.g., thenumbers of times, durations, distances, and locations of theinterruption of the automated driving control and the reasons for theinterruption).

Next, at S14, the CPU 41 determines a planned traveling route (guidanceroute) of the vehicle on the basis of operation of the user from amongthe recommended route and the candidate routes other than therecommended route for which guidance is provided at S13 described above.Herein, the CPU 41 may be configured to determine the recommended routeas the planned traveling route without having the user make a selection.Subsequently, for sections in the automated driving section included inthe planned traveling route from which interruption sections areexcluded, the CPU 41 sets control contents (e.g., going straight,changing lanes to the right, merging) of the automated driving controlperformed on the vehicle.

For example, the example depicted in FIG. 6 is an example of the controlcontents of the automated driving control that is set when sections a tof constitute an automated driving section in the planned traveling routeof the vehicle. In the example depicted in FIG. 6, for the sections a tod, and f obtained by excluding the section e from the sections a to fbecause the section e is an interruption section, the control contentsof the automated driving control are set. The control contents of theautomated driving control are basically determined based on the plannedtraveling route and map information and, for example, for a sectionwhere merging into a main lane in an IC, for example, is necessary,“merging” is set as a control content of the automated driving control.For a section where lane change is necessary to move into anotherexpressway at a JCT, for example, “changing lanes to the right (left)”is set. The information specifying the planned traveling route and thecontrol contents thus set are transmitted to the vehicle control ECU 20through the CAN. Consequently, when the vehicle starts traveling, thevehicle control ECU 20 performs automated driving control after thestart of traveling on the basis of the information received from thenavigation device 1.

The following describes sub-processing of interruption-section couplingprocessing performed at S9 described above with reference to FIG. 7.FIG. 7 is a flowchart of a sub-processing program of theinterruption-section coupling processing.

To begin with, at S21, the CPU 41 determines, for each candidate routeto be processed, whether the number of interruption sections specifiedat S8 described above is more than one.

If it is determined that, for the candidate route to be processed, thenumber of interruption sections specified at S8 described above is morethan one (YES at S21), the process proceeds to S22. If it is determinedthat the number of interruption sections is only one or no interruptionsection is included (NO at S21), the process proceeds to S10 withoutperforming coupling on interruption sections.

The processing from the following S22 to S28 is performed on eachinterruption section included in the candidate route to be processed. Tobegin with, the processing is performed on the interruption sectionclosest to the departure point, and then the processing is performed inorder from the interruption section closer to the departure point. Theprocessing from S22 to S28 is performed on up to the interruptionsection second closest to the destination, and then the process proceedsto S10.

At S22, the CPU 41 acquires each of a start point X1, an end point X2,and a distance L1 (=|X2−X1|) of an interruption section to be processed.

Next, at S23, the CPU 41 acquires each of a start point Y1, an end pointY2, and a distance L2 (=|Y2−Y1|) of an interruption section to besubsequently processed (i.e., an interruption section that is setadjacently to the interruption section to be processed on thedestination side).

Subsequently, at S24, the CPU 41 calculates a distance L3 (=|X2−Y1|)between the interruption section to be processed (hereinafter, called“first interruption section”) and the interruption section to besubsequently processed (hereinafter, called “second interruptionsection”).

Subsequently, at S25, the CPU 41 predicts a vehicle speed V of thevehicle traveling between the first interruption section and the secondinterruption section. The vehicle speed V may be a speed limit (e.g., 80km/h) of a road specified based on map information, or may be an averagevehicle speed in the corresponding section acquired from VICSinformation or probe information. The vehicle speed V is preferablypredicted in consideration of traffic information such as congestioninformation.

Subsequently, at S26, based on the distance L3 calculated at S24described above and the vehicle speed V predicted at S25 describedabove, the CPU 41 calculates a required time Z (=L3/V) that is necessaryfor the vehicle to travel from the end point of the first interruptionsection to the start point of the second interruption section.

Next, at S27, the CPU 41 determines whether the required time Zcalculated at S26 described above is equal to or shorter than apredetermined threshold. The threshold that is a criterion fordetermination at S27 described above is set based on road types and roadshapes, for example, which is a period of time considered to be theupper limit for the interval of switching between the automated drivingcontrol and the manual driving to make the user feel troublesome, and isset to be one minute, for example. Herein, the user may set the value ofthe threshold. Alternatively, at S27 described above, instead of whetherthe required time Z is equal to or shorter than the threshold, the CPU41 may be configured to determine whether the distance L3 between thefirst interruption section and the second interruption section is equalto or shorter than a threshold (e.g., one kilometer).

If it is determined that the required time Z calculated at S26 describedabove is equal to or shorter than the predetermined threshold (YES atS27), the process proceeds to S28. If it is determined that the requiredtime Z calculated at S26 described above is longer than thepredetermined threshold (NO at S27), the process returns to S22, andafter changing the interruption section to be processed, the processingat and after S22 is performed again.

At S28, the CPU 41 connects the first interruption section and thesecond interruption section, thereby setting these interruption sectionsas one continuous interruption section. For example, a case will bedescribed in which two interruption sections of the interruption sectionA and the interruption section B are set adjacently along the candidateroute as depicted in FIG. 8. In this case, if the interruption sectionsare not coupled together at S28 described above, the automated drivingcontrol is performed up to the point X1, the manual driving is performedfrom the point X1 to the point X2, the automated driving control isperformed from the point X2 to the point Y1, the manual driving isperformed from the point Y1 to the point Y2, and the automated drivingcontrol is performed from the point Y2. Thus, switching between theautomated driving control and the manual driving is performedfrequently. In contrast, if the interruption section A and theinterruption section B are connected and one new interruption section Cstarting at X1 and ending at Y2 is set at S28 described above, themanual driving is continuously performed from the point X1 to the pointY2, so that the switching between the automated driving control and themanual driving can be prevented from being performed frequently.

Subsequently, the process returns to S22, and after changing theinterruption section to be processed, the processing at and after S22 isperformed again. The processing from S22 to S28 is performed on up tothe interruption section second closest to the destination, and then theprocess proceeds to S10.

The following describes the automated-driving-control processing programthat the CPU 41 executes in the navigation device 1 according to thefirst embodiment with reference to FIG. 9. FIG. 9 is a flowchart of theautomated-driving-control processing program according to the firstembodiment. This automated-driving-control processing program, which isexecuted at predetermined intervals (e.g., intervals of 100milliseconds) after the planned traveling route (guidance route) of thevehicle has been determined at S14 described above, is a program fordetermining continuation of the automated driving control and newlysetting an interruption section.

To begin with, in the automated-driving-control processing program, atS31, the CPU 41 determines whether the automated driving start button isON. This automated driving start button is disposed on the instrumentpanel, for example, and switches between ON and OFF every time the userdepresses the button. When the automated driving start button is turnedON while the vehicle is traveling in the automated driving section (fromwhich sections specified as interruption sections are excluded), theautomated driving control is started. When the automated driving startbutton is turned OFF while the automated driving control is beingperformed, the automated driving control is ended and switched into themanual driving even if the vehicle is traveling in the automated drivingsection.

If it is determined that the automated driving start button is ON (YESat S31), the process proceeds to S34. If it is determined that theautomated driving start button is not ON (NO at S31), the processproceeds to S32.

At S32, the CPU 41 determines whether the automated driving control ofthe vehicle is being performed.

If it is determined that the automated driving control of the vehicle isbeing performed (YES at S32), the process proceeds to S33. If it isdetermined that the automated driving control of the vehicle is notbeing performed (NO at S32), the automated-driving-control processingprogram is ended.

At S33, the CPU 41 performs end processing of the automated drivingcontrol. Specifically, the CPU 41 transmits an instruction signal forinstructing the vehicle control ECU 20 to end the automated drivingcontrol through the CAN. Consequently, the vehicle ends the automateddriving control and shifts to the manual driving.

At S34, the CPU 41 determines whether the vehicle is located in theautomated driving section on the basis of the current position of thevehicle detected by the current-position detecting unit 11 and mapinformation. The current position of the vehicle is preferred to beprecisely identified by using a high-accuracy location technology. Sucha high-accuracy location technology makes it possible to detecttraveling lanes and the accurate position of the vehicle by detecting,through image recognition, white lines and road marking informationcaptured by a camera mounted on the rear of the vehicle, and further bycomparing the white lines and the road marking information with the mapinformation DB stored in advance. Details of the high-accuracy locationtechnology are already publicly known, and thus description thereof isomitted.

If it is determined that the vehicle is located in the automated drivingsection (YES at S34), the process proceeds to S35. If it is determinedthat the vehicle is not located in the automated driving section (NO atS34), the process proceeds to S32.

At S35, the CPU 41 performs interruption-section detection processing(FIG. 10) described later. This interruption-section detectionprocessing is processing for detecting, other than a section already setas an interruption section, a section where a situation occurs in whichit is difficult for the vehicle to travel by the automated drivingcontrol to newly set this section as an interruption section, asdescribed later using the vehicle exterior camera 19 and sensors, forexample, while the vehicle is traveling.

Next, at S36, the CPU 41 determines whether the automated drivingcontrol is being interrupted. As described above, even while the vehicleis traveling in an automated driving section, when the vehicle islocated in a set interruption section, the automated driving control ofthe vehicle is interrupted and the vehicle travels by the manualdriving.

If it is determined that the automated driving control is beinginterrupted (YES at S36), the process proceeds to S39. If it isdetermined that the automated driving control is not being interrupted(NO at S36), the process proceeds to S37.

At S37, the CPU 41 determines whether the vehicle has entered aninterruption section. Such interruption sections are preset for aplanned traveling route on which the vehicle travels in the route-searchprocessing program (FIG. 2, FIG. 7) described above. The interruptionsections are set also in the interruption-section detection processing(FIG. 10) described later.

If it is determined that the vehicle has entered an interruption section(YES at S37), the process proceeds to S38. At S38, the CPU 41 performsinterruption processing of the automated driving control. Specifically,the CPU 41 transmits an instruction signal for instructing the vehiclecontrol ECU 20 to temporarily interrupt the automated driving controlthrough the CAN. Consequently, the vehicle temporarily interrupts theautomated driving control and shifts to the manual driving. If it isdetermined that the vehicle has not entered an interruption section (NOat S37), the automated driving control is continuously performed.

At S39, the CPU 41 determines whether the vehicle has exited aninterruption section.

If it is determined that the vehicle has exited an interruption section(YES at S39), the process proceeds to S40. At S40, the CPU 41 performsresuming processing of the automated driving control. Specifically, theCPU 41 transmits through the CAN an instruction signal for instructingthe vehicle control ECU 20 to resume the automated driving control thathas been interrupted. Consequently, the vehicle resumes the automateddriving control that has been interrupted and shifts to the automateddriving control from the manual driving. If it is determined that thevehicle has not exited an interruption section (NO at S39), theinterruption of the automated driving control is continued.

The following describes sub-processing of the interruption-sectiondetection processing performed at S35 described above with reference toFIG. 10. FIG. 10 is a flowchart of a sub-processing program of theinterruption-section detection processing.

To begin with, at S41, the CPU 41 acquires the current position of thevehicle on the basis of the detection result of the current-positiondetecting unit 11. The current position of the vehicle is preferablyidentified by using the high-accuracy location technology.

Next, at S42, the CPU 41 acquires route information ahead of the vehiclein the traveling direction. For example, the CPU 41 acquires routeinformation within one kilometer from the current position of thevehicle along the planned traveling route.

Subsequently, at S43, the CPU 41 determines whether connection isestablished with an external server storing interruption records of theautomated driving control of other vehicles and/or a traffic informationserver such as a VICS center.

If it is determined that connection is established with an externalserver storing interruption records of the automated driving control ofother vehicles and/or a traffic information server such as a VICS center(YES at S43), the CPU 41 acquires (at S44) the latest interruptionrecords of the automated driving control and/or the latest trafficinformation for sections (hereinafter, called “detection targetsections”) ahead of the vehicle in the traveling direction for which theroute information is acquired from the server at S42 described above. Ifit is determined that connection is not established with an externalserver storing interruption records of the automated driving control ofother vehicles or a traffic information server such as a VICS center (NOat S43), the process proceeds to S45.

At S45, the CPU 41 determines whether connection is established with acamera and/or sensors, for example, for detecting external environmentof the vehicle. Examples of the sensors include a millimeter wave radarfor detecting an obstacle, a rain sensor for detecting rainfall and snowcover, and an illuminance sensor.

If it is determined that connection is established with a camera and/orsensors for detecting external environment of the vehicle (YES at S45),external environment around the vehicle is detected by the camera and/orthe sensors connected (S46). If it is determined that connection is notestablished with a camera or sensors for detecting external environmentof the vehicle (NO at S45), the process proceeds to S47.

Subsequently, at S47, based on the interruption records and/or thetraffic information acquired at S44 described above and the externalenvironment detected at S46 described above, the CPU 41 determineswhether a section where a situation in which it is difficult for thevehicle to travel by the automated driving control occurs exists amongthe sections, except a section already set as an interruption section,ahead of the vehicle in the traveling direction for which the routeinformation is acquired at S42 described above. If it is determined thata section where a situation in which it is difficult for the vehicle totravel by the automated driving control occurs exists, this section isnewly specified as an interruption section. The interruption sectionspecified at S47 described above is an interruption section that couldnot specified during route search but can be specified first when thevehicle reaches an actual place. For example, a section that falls underany of the conditions (6) to (9) below is specified as an interruptionsection.

(6) a section for which an interruption record did not exist during theroute search but, during a period until the vehicle reaches the actualplace, an interruption record is newly generated when another vehicleinterrupts the automated driving control.

(7) a section where lanes are newly restricted due to an accident,construction, or a fallen object, for example, after the route search,and which lane is restricted cannot be identified.

(8) a section where the fact that lane markings (e.g., a roadwaycenterline, a lane boundary, a roadway outside line) disappear or fadeto the extent that the lane markings cannot be recognized with a camerais newly detected by capturing images of the road surface with thecamera.(9) a section for which the weather becomes so bad (e.g., heavy rain,dense fog, snow cover, icy road) that it is difficult to performdetection with a camera and sensors or it is difficult to performvehicle control, which could not be predicted during the route search.

Next, at S48, the CPU 41 determines whether an interruption section hasbeen newly specified at S47 described above.

If it is determined that an interruption section has been newlyspecified (YES at S48), the process proceeds to S49. If it is determinedthat no interruption section has been newly specified (NO at S48), theprocess proceeds to S36 without newly setting an interruption section inparticular.

At S49, the CPU 41 performs the interruption-section coupling processing(FIG. 7) described above. The interruption-section coupling processingis processing for connecting interruption sections that satisfy acertain condition and are adjacently arranged along a candidate route asdescribed above to set one continuous interruption section. Thus,because an interruption section is newly specified at S47 describedabove, decision about coupling of interruption sections is made for thisnew interruption section, and if necessary, the coupling of interruptionsections is performed. Note that when the vehicle speed V of the vehicletraveling between the first interruption section and the secondinterruption section is predicted at S25, the current vehicle speed ofthe vehicle (at the time when the new interruption section is specified)is preferably acquired with the vehicle speed sensor 23, and the vehiclespeed V of the vehicle traveling between the first interruption sectionand the second interruption section is preferably predicted to be thisacquired vehicle speed.

Next, at S50, the CPU 41 changes the control contents of the automateddriving control set at S14 described above on the basis of the newlyspecified and coupled interruption section. Specifically, for a sectionthat is newly set as an interruption section, the CPU 41 changes thecontrol contents such that the automated driving control is notperformed. Accordingly, the control contents of the automated drivingcontrol for other sections are changed if necessary. The controlcontents thus changed are transmitted to the vehicle control ECU 20through the CAN. Consequently, it is possible to perform the automateddriving control into which the newly specified and coupled interruptionsection is reflected.

As described above in detail, with the navigation device 1, the routesearching method with the navigation device 1, and the computer programexecuted in the navigation device 1 according to the first embodiment,when a recommended route from a departure point to a destinationincluding an automated driving section where automated driving controlof the vehicle is performed is searched for, a plurality of candidateroutes that are candidates for the recommended route are acquired (S4);for each of the candidate routes acquired, an interruption section wherethe automated driving control is interrupted in the automated drivingsection included in the candidate route is specified (S8, S9); based onthe interruption section specified, for each of the candidate routes,interruption information indicating that the automated driving controlis interrupted in the automated driving section included in thecandidate route is acquired (S10); and, based on the interruptioninformation acquired, the recommended route is selected from among thecandidate routes (S12). Thus, when a route to a destination is searchedfor, a recommended route can be selected in consideration of aninterruption section where automated driving control is interrupted. Byusing interruption information on interruption of the automated drivingcontrol, while preventing the occurrence of a situation in which anexcessively long roundabout route is searched for or route search fails,it is possible to select a more appropriate recommended route for theuser.

Second Embodiment

The following describes a navigation device according to a secondembodiment with reference to FIG. 11. In the following description,reference numerals that are the same as those in the structure of thenavigation device 1 according to the first embodiment depicted in FIG. 1to FIG. 10 described above indicate components that are the same orequivalent as those in the navigation device 1 according to the firstembodiment, for example.

The schematic structure of the navigation device according to the secondembodiment is substantially the same as the structure of the navigationdevice 1 according to the first embodiment. The various types of controlprocessing thereof are substantially the same as the control processingof the navigation device 1 according to the first embodiment. However,these are different in the following point. In the navigation device 1according to the first embodiment, the navigation device 1 determines,during route search, an interruption section where the automated drivingcontrol is interrupted, and the vehicle control ECU 20 controls thevehicle in accordance with the interruption section determined by thenavigation device 1 during the route search. By contrast, in thenavigation device according to the second embodiment, the navigationdevice 1 only specifies, during route search, a section (hereinafter,called “interruption-predicted section”) where there is a possibilitythat the automated driving control will be interrupted, and theinterruption-predicted section thus specified does not affect whetherthe automated driving is actually interrupted (i.e., determination ofwhether the automated driving control is interrupted is determined bythe navigation device and the vehicle control ECU 20 while the vehicleis traveling in the automated driving section).

The route-search processing program executed by the CPU 41 in thenavigation device according to the second embodiment is basically thesame in processing as the route-search processing program (FIG. 2)according to the first embodiment except that interruption sections arereplaced with interruption-predicted sections. Theautomated-driving-control processing program is also basically the samein processing as the automated-driving-control processing program (FIG.9) according to the first embodiment. However, in the route-searchprocessing program according to the second embodiment, a section wherethere is a possibility that the automated driving control will beinterrupted is only predicted, so that interruption-predicted sectionsspecified at S8 and S9 described above may be different from sectionswhere the automated driving control is actually interrupted. Thus, thecontrol contents (see FIG. 6) of the automated driving controldetermined at S14 are changed as needed while the vehicle is traveling.

The interruption-section coupling processing at S9 is also performed onthe interruption-predicted sections. Consequently, wheninterruption-predicted sections where there is a possibility that theautomated driving control will be interrupted are included in arecommended route or other candidate routes, interruption-predictedsections that are adjacently arranged can be connected to set onecontinuous interruption-predicted section. Thus, it is possible toaccurately match the interruption-predicted sections to the sectionswhere the automated driving control is actually interrupted. It is alsopossible to modify the shapes of the interruption-predicted sectionsinto shapes that the user can easily understand, without making theshapes complicated.

In the navigation device according to the second embodiment, at S10described above, based on interruption-predicted sections set at S8 andS9 described above, the CPU 41 acquires interruption-predictinginformation indicating that the automated driving control is predictedto be interrupted for each candidate route to be processed. Theinterruption-predicting information contains probabilities that theautomated driving control will be actually interrupted in theinterruption-predicted sections, in addition to the number of times,durations, distances, and locations of the predicted interruption of theautomated driving control in the candidate route to be processed and thereasons for the interruption.

At S11, when calculating the decision value D for the candidate route,the CPU 41 may use the probabilities that the automated driving controlwill be interrupted to calculate the additional value α, in addition tothe number of times, the durations, the distances, the locations of thepredicted interruption of the automated driving control and the reasonsfor the interruption.

For example, when the probabilities that the automated driving controlwill be interrupted are used to calculate the additional value α, thiscalculation is performed such that a higher probability of interruptionproduces a larger additional value α. FIG. 11 is a figure illustratingan example of correspondence between additional values α andprobabilities that automated driving control will be interrupted. Forexample, in the case where the candidate route includes a section thatis set as an interruption-predicted section because merging or lanechange is performed in a short section (e.g., 500 meters or shorter),particularly when the candidate route includes an interruption-predictedsection where merging or lane change is performed in a distance longerthan 100 meters and equal to or shorter than 500 meters, because mergingor lane change can be performed in a relatively easy manner even by theautomated driving control, the probability that the automated drivingcontrol will be interrupted is low, and the additional value α iscalculated to be “1”. When the candidate route includes aninterruption-predicted section where merging or lane change is performedin a distance equal to or shorter than 100 meters, because it isdifficult to perform merging or lane change by the automated drivingcontrol, the probability that the automated driving control will beinterrupted is high, and the additional value α is calculated to be “2”.When the road shape of the interruption-predicted section where mergingor lane change is performed cannot be identified from map information,because the automated driving control cannot be basically performed, theadditional value α is calculated to be “3”. In the case where thecandidate route includes a section that is set as aninterruption-predicted section because of snow cover or an icy road whenthe vehicle travels, particularly when the candidate route includes aninterruption-predicted section for which icy road information exists inVICS information, the probability that the weather will become so badthat it is difficult to perform detection with a camera and sensors orit is difficult to perform vehicle control and accordingly the automateddriving control will be interrupted when the vehicle travels in thissection is determined to be remarkably high, and the additional value αis calculated to be “3”. In the case where the candidate route includesan interruption-predicted section for which VICS information does notexist but the snowfall probability is high according to the weatherforecast (e.g., 80% or higher), the probability that the weather willbecome so bad that it is difficult to perform detection with a cameraand sensors or it is difficult to perform vehicle control andaccordingly the automated driving control will be interrupted when thevehicle travels in this section is determined to be high, and theadditional value α is calculated to be “2”. In the case where thecandidate route includes an interruption-predicted section for whichVICS information does not exist and the snowfall probability is low(e.g., lower than 80%) according to the weather forecast, theprobability that the weather will become so bad that it is difficult toperform detection with a camera and sensors or it is difficult toperform vehicle control and accordingly the automated driving controlwill be interrupted when the vehicle travels in this section isdetermined to be low, and the additional value α is calculated to be“1”. In the same manner, for other reasons, the additional values arecalculated based on the probabilities that the automated driving controlwill be interrupted as depicted in FIG. 11. Herein, when there are aplurality of interruption-predicted sections, the additional value α maybe calculated for each of the interruption-predicted sections, and thedecision value D may be calculated by using only the largest additionalvalue α, or the decision value D may be calculated by adding all theadditional values α calculated to the required time T. Consequently, thedecision value D of a candidate route including aninterruption-predicted section where the automated driving control isinterrupted with a higher probability can be calculated to be larger(which makes it difficult for this route to be selected as a recommendedroute), and thus a more appropriate recommended route can be selected.

Herein, the structure for calculating the decision values D of thecandidate routes on the basis of the numbers of times, durations,distances, and locations of the predicted interruption of the automateddriving control and the reasons for the interruption is the same as thatin the first embodiment, and thus description thereof is omitted.

In the navigation device according to the second embodiment, whenguidance about information on a recommended route and other candidateroutes other than the recommended route is provided at S13, the guidancemay be provided in a manner depending on the probabilities that theautomated driving control will be interrupted. Specifically, displaycolors or display patterns of interruption-predicted sections includedin a recommended route, for example, are changed in accordance with theinterruption probabilities. For example, in the route guidance screen 51depicted in FIG. 5, an interruption-predicted section where theinterruption probability is predicted to be high (80% or higher) can bedisplayed in red, an interruption-predicted section where theinterruption probability is predicted to be medium (lower than 80% andequal to or higher than 50%) can be displayed in green, and aninterruption-predicted section where the interruption probability ispredicted to be low (lower than 50%) can be displayed in blue.Consequently, by watching the route guidance screen 51, the user caneasily understand in which section and at what probability the automateddriving control will be interrupted.

As described above in detail, with the navigation device, the routesearching method with the navigation device, and the computer programexecuted in the navigation device according to the second embodiment,when a recommended route from a departure point to a destinationincluding an automated driving section where automated driving controlof the vehicle is performed is searched for, a plurality of candidateroutes that are candidates for the recommended route are acquired; foreach of the candidate routes acquired, an interruption-predicted sectionwhere there is a possibility that the automated driving control will beinterrupted in the automated driving section included in the candidateroute is specified; based on the interruption-predicted sectionspecified, for each of the candidate routes, interruption-predictinginformation indicating that the automated driving control is predictedto be interrupted in the automated driving section included in thecandidate route is acquired; and, based on the interruption-predictinginformation acquired, the recommended route is selected from among thecandidate routes. Thus, when a route to a destination is searched for, arecommended route can be selected in consideration of aninterruption-predicted section where there is a possibility thatautomated driving control will be interrupted. By usinginterruption-predicting information on interruption prediction of theautomated driving control, while preventing the occurrence of asituation in which an excessively long roundabout route is searched foror route search fails, it is possible to select a more appropriaterecommended route for the user.

It should be noted that the present disclosure is not limited to theembodiments described above, and as a matter of course, variousimprovements and modifications can be made within a scope not departingfrom the gist of the present disclosure.

For example, in the first embodiment and the second embodiment, sectionswhere the automated driving control is interrupted or may be interruptedin an automated driving section are specified (S8, S47). However,sections where the manual driving is interrupted to perform theautomated driving control or sections where there is a possibility thatthe manual driving will be interrupted to perform the automated drivingcontrol may be specified. In this case, sections that do not fall underany of the conditions (1) to (5) above are sections where the manualdriving is interrupted to perform the automated driving control orsections where there is a possibility that the manual driving will beinterrupted to perform the automated driving control. For the sectionsthus specified, the interruption-section coupling processing depicted inFIG. 7 can be performed in the same manner. Furthermore, each decisionvalues D is calculated based on information indicating that the manualdriving is interrupted or is predicted to be interrupted, whereby arecommended route is selected. In the calculation of the decision valueD at S11, in contrast to the first embodiment and the second embodiment,the additional value α is set to be a smaller value as the number oftimes, durations, or distances of the interruption of the manual drivingor predicted to be interrupted increase. The additional value α is setto be a smaller value when the location where the manual driving isinterrupted or is predicted to be interrupted is located closer to thedestination on the candidate route.

In the first embodiment and the second embodiment, the navigation device1 is configured to set control contents (e.g., going straight, changinglanes to the right, merging) of the automated driving control that isperformed on the vehicle. Alternatively, the vehicle control ECU 20 maybe configured to set the control contents of automated driving. Thecontrol contents of the automated driving control do not necessarilyhave to be set during route search, and may be set by the time thevehicle reaches the automated driving section.

In the first embodiment and the second embodiment, theinterruption-section detection processing (FIG. 10) described above isperformed when the vehicle is traveling in an automated driving section,but may be performed only when the vehicle is traveling in aninterruption section in particular. In this case, when an interruptionsection is newly specified at S47, an interruption section where thevehicle is currently located and the interruption section newlyspecified are coupled together at S49. Furthermore, when theinterruption-section detection processing (FIG. 10) is performed onlywhen the vehicle is traveling in the interruption section, a detectionrange (i.e., a range within which route information is acquired at S42,a range within which interruption information and traffic informationare acquired at S44, and a detection range of a camera and sensors atS46) within which a section where the automated driving control needs tobe interrupted is newly detected may be set ahead of the vehicle in thetraveling direction in accordance with the vehicle speed of the vehicle.For example, as the vehicle speed of the vehicle increases, thedetection range is set wider. Consequently, the required time Z from theend point of the interruption section where the vehicle is currentlylocated to the start point of the interruption section newly specifiedis inevitably equal to or shorter than the threshold, which enables theprocessing at S22 to S27 to be omitted.

In the first embodiment and the second embodiment, description has beenmade assuming that the automated driving control for traveling in anautomated way without driving operation of the user means that, out ofoperations of the vehicle, all of accelerator operation, brakeoperation, and steering operation that are operations related to vehiclebehavior are controlled by the vehicle control ECU 20. However, as theautomated driving control, the vehicle control ECU 20 may be configuredto control, out of operations of the vehicle, at least one ofaccelerator operation, brake operation, and steering operation that areoperations related to vehicle behavior. By contrast, description is madeassuming that the manual driving by driving operation of the user meansthat, out of operations of the vehicle, all of accelerator operation,brake operation, and steering operation that are operations related tovehicle behavior are performed by the user.

In the first embodiment and the second embodiment, the navigation device1 is configured to perform the route change processing program (FIG. 2)and the automated driving control program (FIG. 9). Alternatively, thevehicle control ECU 20 may be configured to perform these programs. Inthis case, the vehicle control ECU 20 is configured to acquire thecurrent position of the vehicle, map information, and trafficinformation, for example, from the navigation device 1.

The present disclosure can be also applied to devices having a routesearch function in addition to navigation devices. For example, thepresent disclosure can be applied to mobile phones, smart phones, tabletterminals, personal computers, for example (hereinafter, called “mobileterminals, etc.”). The present disclosure can be also applied to asystem including a server and mobile terminals, etc. In this case, anyof the server and the mobile terminals, etc. may be configured toperform the respective steps of the route change processing program(FIG. 2) and the automated driving control program (FIG. 9) describedabove. Note that when the present disclosure is applied to the mobileterminals, etc., connection needs to be established such that the mobileterminals, etc. can communicate with vehicles that can perform automateddriving control (regardless of whether the connection is wired orwireless).

Examples in which the route searching system according to the presentdisclosure is embodied have been described in the foregoing, but theroute searching system may have structures described below. In thiscase, effects described below are obtained.

For example, the first structure is as follows.

The route searching system includes interruption information thatcontains any of number of times, a duration, a distance, and a locationof the interruption of the automated driving control and a reason forthe interruption.

With the route searching system having this structure, the recommendedroute can be selected in consideration of how the automated drivingcontrol is interrupted in detail. Thus, it is possible to select a moreappropriate recommended route for the user.

The second structure is as follows.

The route searching system includes interruption-predicting informationthat contains any of the number of times, a duration, a distance, and alocation of the predicted interruption of the automated driving controland a reason for the interruption.

With the route searching system having this structure, the recommendedroute can be selected in consideration of how the automated drivingcontrol may be interrupted in detail. Thus, it is possible to select amore appropriate recommended route for the user.

The third structure is as follows.

The route searching system includes recommended-route selecting codethat acquires, for each of the candidate routes, a required timenecessary for the vehicle to travel on the candidate route, calculates adecision value obtained by adding an additional value based on theinterruption information or the interruption-predicting information tothe required time for each of the candidate routes, and compares thedecision values of the respective candidate routes to select therecommended route.

With the route searching system having this structure, by using such adecision value calculated from specific values as an index for selectinga recommended route, a recommended route suitable for the user can beeasily selected even if there are many candidate routes. Because theevaluation index is converted into a numerical form, it is possible tosimplify the processing for selecting a recommended route therebyreducing the processing load.

The fourth structure is as follows.

The route searching system includes recommended-route selecting codethat selects, from among the candidate routes, a candidate route havingthe decision value that is smallest as the recommended route.

With the route searching system having this structure, the decisionvalues of the respective candidate routes are compared to select acandidate route having the smallest decision value as a recommendedroute, thus a recommended route suitable for the user can be accuratelyand quickly selected even if there are many candidate routes.

The fifth structure is as follows.

The route searching system includes an additional value that is set tobe a larger value as the number of times, the duration, or the distanceof the interruption or the predicted interruption of the automateddriving control increases.

With the route searching system having this structure, a candidate routeon which the automated driving control is less frequently interruptedcan be selected with a higher priority as a recommended route. Thus, amore appropriate recommended route can be selected for a user who wantsto travel by the automated driving control.

The sixth structure is as follows.

The route searching system includes an additional value that is set tobe a larger value at a location, where the automated driving control isinterrupted or predicted to be interrupted, that is closer to thedestination on each of the candidate routes.

With the route searching system having this structure, a candidate routeon which the automated driving control is less frequently interrupted inthe latter half of the route where the user feels more fatigue due todriving can be selected with a higher priority as a recommended route.Thus, a more appropriate recommended route can be selected for a userwho wants to travel by the automated driving control.

The seventh structure is as follows.

In the route searching system the interruption-predicting informationcontains a probability that the automated driving control will beinterrupted in the interruption-predicted section, and therecommended-route selecting code acquires, for each of the candidateroutes, a required time necessary for the vehicle to travel on thecandidate route, calculates a decision value obtained by adding anadditional value based on the probability to the required time for eachof the candidate routes, and compares the decision values of therespective candidate routes to select the recommended route.

With the route searching system having this structure, by using such adecision value calculated based on the probability that the automateddriving control will be interrupted as an index for selecting arecommended route, a recommended route suitable for the user can beeasily selected even if there are many candidate routes. Because theevaluation index is converted into a numerical form, it is possible tosimplify the processing for selecting a recommended route therebyreducing the processing load.

The eighth structure is as follows.

In the route searching system the additional value is set to be a largervalue as the probability that the automated driving control will beinterrupted increases.

With the route searching system having this structure, a candidate routeon which the probability that the automated driving control will beinterrupted is lower can be selected with a higher priority as arecommended route. Thus, a more appropriate recommended route can beselected for a user who wants to travel by the automated drivingcontrol.

The ninth structure is as follows.

In the route searching system the interruption section specifying codeor the interruption-predicted section specifying code uses any of a roadshape, a lane marking, traffic information, weather information, and apast interruption record of the automated driving control to specify theinterruption section or the interruption-predicted section.

With the route searching system having this structure, a section where asituation occurs in which it is difficult for the vehicle to travel bythe automated driving control can be appropriately specified as aninterruption section or an interruption-predicted section.

The tenth structure is as follows.

The route searching system further include recommended route guidancecode for providing guidance for the recommended route selected by therecommended-route selecting code in a manner distinguishing theinterruption section or the interruption-predicted section.

With the route searching system having this structure, the user caneasily understand where the automated driving control is interruptedwhen traveling on the recommended route.

The eleventh structure is as follows.

The route searching system further includes control content setting codefor, for a section in the automated driving section included in therecommended route selected by the recommended-route selecting code fromwhich the interruption section or the interruption-predicted section isexcluded, setting control contents of the automated driving control thatis performed on the vehicle.

With the route searching system having this structure, considering inadvance a section where the automated driving control is interrupted, itis possible to set the control contents of the automated driving controlthat is performed on the vehicle traveling on a recommended route. Thiseliminates the need of setting the control contents of the automateddriving control while traveling, and also eliminates the need to modifythe set control contents every time the automated driving control isinterrupted, thereby making it possible to reduce the processing loadrelated to the automated driving control.

The twelfth structure is as follows.

The route searching system includes route candidate acquisition codethat acquires as the candidate routes, out of routes from the departurepoint to the destination, a certain number of routes that are specifiedin ascending order of cost added value that is an accumulated value of asearch cost.

With the route searching system having this structure, the number ofcandidate routes that are candidates for a recommended route can benarrowed down to the certain number in advance based on the cost addedvalue.

The thirteenth structure is as follows.

The route searching system further includes driving intentionacquisition code for acquiring whether a user wants to travel by theautomated driving control in the automated driving section, and when theuser wants to travel by the automated driving control in the automateddriving section, the route searching system determines that the vehicletravels by the automated driving control in an automated driving sectionincluded in the candidate routes to search for the recommended route,and when the user does not want to travel by the automated drivingcontrol in the automated driving section, the route searching systemdetermines that the vehicle travels by manual driving in an automateddriving section included in the candidate routes to search for therecommended route.

With the route searching system having this structure, also consideringthe user's intention on whether to travel by the automated drivingcontrol, it is possible to search for an appropriate recommended route.

The fourteenth structure is as follows.

A route searching system that searches for a recommended route from adeparture point to a destination including an automated driving sectionwhere a vehicle is allowed to perform automated driving control inaddition to manual driving includes: route candidate acquisition codesfor acquiring a plurality of candidate routes that are candidates forthe recommended route; manual interruption section specifying code for,for each of the candidate routes acquired by the route candidateacquisition code, specifying a manual-driving interruption section wherethe manual driving is interrupted and the automated driving control isperformed in the automated driving section included in the candidateroute; manual interruption information acquisition code for, based onthe manual-driving interruption section specified by the manualinterruption section specifying code, for each of the candidate routes,acquiring interruption information indicating that the manual driving isinterrupted in the automated driving section included in the candidateroute; and recommended-route selecting code for selecting therecommended route including the manual-driving interruption section fromamong the candidate routes, based on the interruption informationacquired by the manual interruption information acquisition code.

With the route searching system having this structure, when searchingfor a route to a destination, it is possible to select a recommendedroute considering an interruption section where the manual driving isinterrupted (i.e., a section where the automated driving control isperformed). By using interruption information on interruption of themanual driving, while preventing the occurrence of a situation in whichan excessively long roundabout route is searched for or route searchfails, it is possible to select a more appropriate recommended route forthe user.

The fifteenth structure is as follows.

A route searching system that searches for a recommended route from adeparture point to a destination including an automated driving sectionwhere a vehicle is allowed to perform automated driving control inaddition to manual driving includes: route candidate acquisition codefor acquiring a plurality of candidate routes that are candidates forthe recommended route; manual-interruption-predicted section specifyingcode for, for each of the candidate routes acquired by the routecandidate acquisition code, specifying amanual-driving-interruption-predicted section where there is apossibility that the manual driving will be interrupted and theautomated driving control will be performed in the automated drivingsection included in the candidate route; manual-interruption-predictinginformation acquisition code for, based on themanual-driving-interruption-predicted section specified by themanual-interruption-predicted section specifying code, for each of thecandidate routes, acquiring interruption-predicting informationindicating that the manual driving is predicted to be interrupted in theautomated driving section included in the candidate route; andrecommended-route selecting code for selecting the recommended routeincluding the manual-driving-interruption-predicted section from amongthe candidate routes, based on the interruption-predicting informationacquired by the manual-interruption-predicting information acquisitioncode.

With the route searching system having this structure, when searchingfor a route to a destination, it is possible to select a recommendedroute considering an interruption-predicted section where there is apossibility that the manual driving will be interrupted (i.e., a sectionwhere the automated driving control is predicted to be performed). Byusing interruption-predicting information on interruption prediction ofthe manual driving, while preventing the occurrence of a situation inwhich an excessively long roundabout route is searched for or routesearch fails, it is possible to select a more appropriate recommendedroute for the user.

DESCRIPTION OF THE REFERENCE NUMERALS

-   -   1 navigation device    -   13 navigation ECU    -   14. operating unit    -   15 liquid crystal display    -   41 CPU    -   42 RAM    -   43 ROM    -   51 route guidance screen    -   52 information window    -   54 recommended route    -   55 candidate route    -   56 section-specifying line segment    -   57 interruption icon

The invention claimed is:
 1. A route searching system that searches fora recommended route from a departure point to a destination including anautomated driving section where automated driving control of a vehicleis performed, the route searching system comprising: route candidateacquisition code for acquiring a plurality of candidate routes that arecandidates for the recommended route; interruption section specifyingcode, for each of the candidate routes acquired by the route candidateacquisition code, specifying an interruption section where automateddriving control is interrupted in the automated driving section includedin the candidate route; interruption information acquisition code, basedon the interruption section specified by the interruption sectionspecifying code, for each of the candidate routes, acquiringinterruption information indicating that the automated driving controlis interrupted in the automated driving section included in thecandidate route; recommended-route selecting code for selecting therecommended route including the interruption section from among thecandidate routes, based on the interruption information acquired by theinterruption information acquisition code; and a display that displaysinformation based on the recommended route or a speaker that outputsaudio information based on the recommended route, wherein therecommended-route selecting code acquires, for each of the candidateroutes, a required time necessary for the vehicle to travel on thecandidate route, calculates a decision value obtained by adding anadditional value based on the interruption information to the requiredtime for each of the candidate routes, and compares the decision valuesof the respective candidate routes to select the recommended route. 2.The route searching system according to claim 1, wherein theinterruption information contains any of number of times, a duration, adistance, and a location of the interruption of the automated drivingcontrol and a reason for the interruption.
 3. The route searching systemaccording to claim 1, wherein the recommended-route selecting codeselects, from among the candidate routes, a candidate route having thedecision value that is smallest as the recommended route.
 4. The routesearching system according to claim 1, wherein the additional value isset to be a larger value as the number of times, the duration, or thedistance for which the automated driving control is interrupted orpredicted to be interrupted increases.
 5. The route searching systemaccording to claim 1, wherein the additional value is set to be a largervalue at a location, where the automated driving control is interruptedor predicted to be interrupted, that is closer to the destination oneach of the candidate routes.
 6. The route searching system according toclaim 1, wherein the interruption section specifying code uses any of aroad shape, a lane marking, traffic information, weather information,and a past interruption record of the automated driving control tospecify the interruption section or the interruption-predicted section.7. The route searching system according to claim 1, further comprisingrecommended route guidance code for providing guidance for therecommended route selected by the recommended-route selecting code in amanner distinguishing the interruption section or theinterruption-predicted section.
 8. The route searching system accordingto claim 1, further comprising control content setting code, for asection in the automated driving section included in the recommendedroute selected by the recommended-route selecting code from which theinterruption section or the interruption-predicted section is excluded,setting control contents of the automated driving control that isperformed on the vehicle.
 9. The route searching system according toclaim 1, wherein the route candidate acquisition code acquires as thecandidate routes, out of routes from the departure point to thedestination, a certain number of routes that are specified in ascendingorder of cost added value that is an accumulated value of a search cost.10. The route searching system according to claim 1, further comprisingdriving intention acquisition code for acquiring whether a user wants totravel by the automated driving control in the automated drivingsection, wherein when the user wants to travel by the automated drivingcontrol in the automated driving section, the route searching systemdetermines that the vehicle travels by the automated driving control inan automated driving section included in the candidate routes to searchfor the recommended route, and when the user does not want to travel bythe automated driving control in the automated driving section, theroute searching system determines that the vehicle travels by manualdriving in an automated driving section included in the candidate routesto search for the recommended route.
 11. A route searching system thatsearches for a recommended route from a departure point to a destinationincluding an automated driving section where automated driving controlof a vehicle is performed, the route searching system comprising: routecandidate acquisition code for acquiring a plurality of candidate routesthat are candidates for the recommended route; interruption-predictedsection specifying code, for each of the candidate routes acquired bythe route candidate acquisition code, specifying aninterruption-predicted section where there is a possibility thatautomated driving control will be interrupted in the automated drivingsection included in the candidate route; interruption-predictinginformation acquisition code, based on the interruption-predictedsection specified by the interruption-predicted section specifying code,for each of the candidate routes, acquiring interruption-predictinginformation indicating that the automated driving control is predictedto be interrupted in the automated driving section included in thecandidate route; recommended-route selecting code for selecting therecommended route including the interruption-predicted section fromamong the candidate routes, based on the interruption-predictinginformation acquired by the interruption-predicting informationacquisition code; and a display that displays information based on therecommended route or a speaker that outputs audio information based onthe recommended route, wherein the recommended-route selecting codeacquires, for each of the candidate routes, a required time necessaryfor the vehicle to travel on the candidate route, calculates a decisionvalue obtained by adding an additional value based on theinterruption-predicting information to the required time for each of thecandidate routes, and compares the decision values of the respectivecandidate routes to select the recommended route.
 12. The routesearching system according to claim 11, wherein theinterruption-predicting information contains any of number of times, aduration, a distance, and a location of the predicted interruption ofthe automated driving control and a reason for the interruption.
 13. Theroute searching system according to claim 11, wherein theinterruption-predicting information contains a probability that theautomated driving control will be interrupted in the interruptionpredicting section, and the recommended-route selecting code acquires,for each of the candidate routes, a required time necessary for thevehicle to travel on the candidate route, calculates a decision valueobtained by adding an additional value based on the probability to therequired time for each of the candidate routes, and compares thedecision values of the respective candidate routes to select therecommended route.
 14. The route searching system according to claim 13,wherein the additional value is set to be a larger value as theprobability that the automated driving control will be interruptedincreases.
 15. A route searching system that searches for a recommendedroute from a departure point to a destination including an automateddriving section where a vehicle is allowed to perform automated drivingcontrol in addition to manual driving, the route searching systemcomprising: route candidate acquisition code for acquiring a pluralityof candidate routes that are candidates for the recommended route;manual interruption section specifying code, for each of the candidateroutes acquired by the route candidate acquisition code, specifying amanual-driving interruption section where the manual driving isinterrupted and the automated driving control is performed in theautomated driving section included in the candidate route; manualinterruption information acquisition code, based on the manual-drivinginterruption section specified by the manual interruption sectionspecifying code, for each of the candidate routes, acquiringinterruption information indicating that the manual driving isinterrupted in the automated driving section included in the candidateroute; recommended-route selecting code for selecting the recommendedroute including the manual-driving interruption section from among thecandidate routes, based on the interruption information acquired by themanual interruption information acquisition code; and a display thatdisplays information based on the recommended route or a speaker thatoutputs audio information based on the recommended route, wherein therecommended-route selecting code acquires, for each of the candidateroutes, a required time necessary for the vehicle to travel on thecandidate route, calculates a decision value obtained by adding anadditional value based on the interruption information to the requiredtime for each of the candidate routes, and compares the decision valuesof the respective candidate routes to select the recommended route. 16.A route searching system that searches for a recommended route from adeparture point to a destination including an automated driving sectionwhere a vehicle is allowed to perform automated driving control inaddition to manual driving, the route searching system comprising: routecandidate acquisition code for acquiring a plurality of candidate routesthat are candidates for the recommended route;manual-interruption-predicted section specifying code, for each of thecandidate routes acquired by the route candidate acquisition code,specifying a manual-driving-interruption-predicted section where thereis a possibility that the manual driving will be interrupted and theautomated driving control will be performed in the automated drivingsection included in the candidate route; manual-interruption-predictinginformation acquisition code, based on themanual-driving-interruption-predicted section specified by themanual-interruption-predicted section specifying code, for each of thecandidate routes, acquiring interruption-predicting informationindicating that the manual driving is predicted to be interrupted in theautomated driving section included in the candidate route;recommended-route selecting code for selecting the recommended routeincluding the manual-driving-interruption-predicted section from amongthe candidate routes, based on the interruption-predicting informationacquired by the manual-interruption-predicting information acquisitioncode; and a display that displays information based on the recommendedroute or a speaker that outputs audio information based on therecommended route, wherein the recommended-route selecting codeacquires, for each of the candidate routes, a required time necessaryfor the vehicle to travel on the candidate route, calculates a decisionvalue obtained by adding an additional value based on theinterruption-predicting information to the required time for each of thecandidate routes, and compares the decision values of the respectivecandidate routes to select the recommended route.
 17. A route searchingmethod for searching for a recommended route from a departure point to adestination including an automated driving section where automateddriving control of a vehicle is performed, the route searching methodcomprising: a step of, by route candidate acquisition code, acquiring aplurality of candidate routes that are candidates for the recommendedroute; a step of, by interruption section specifying code, for each ofthe candidate routes acquired by the route candidate acquisition code,specifying an interruption section where automated driving control isinterrupted in the automated driving section included in the candidateroute; a step of, by interruption information acquisition code, based onthe interruption section specified by the interruption sectionspecifying code, for each of the candidate routes, acquiringinterruption information indicating that the automated driving controlis interrupted in the automated driving section included in thecandidate route; a step of, by recommended-route selecting code,selecting the recommended route including the interruption section fromamong the candidate routes, based on the interruption informationacquired by the interruption information acquisition code; and a stepof, displaying information based on the recommended route on a displayor outputting audio information based on the recommended route to aspeaker, wherein the recommended-route selecting code acquires, for eachof the candidate routes, a required time necessary for the vehicle totravel on the candidate route, calculates a decision value obtained byadding an additional value based on the interruption information to therequired time for each of the candidate routes, and compares thedecision values of the respective candidate routes to select therecommended route.
 18. A route searching method for searching for arecommended route from a departure point to a destination including anautomated driving section where automated driving control of a vehicleis performed, the route searching method comprising: a step of, by routecandidate acquisition code, acquiring a plurality of candidate routesthat are candidates for the recommended route; a step of, byinterruption-predicted section specifying code, for each of thecandidate routes acquired by the route candidate acquisition code,specifying an interruption-predicted section where there is apossibility that automated driving control will be interrupted in theautomated driving section included in the candidate route; a step of, byinterruption-predicting information acquisition code, based on theinterruption-predicted section specified by the interruption-predictedsection specifying code, for each of the candidate routes, acquiringinterruption-predicting information indicating that the automateddriving control is predicted to be interrupted in the automated drivingsection included in the candidate route; a step of, by recommended-routeselecting code, selecting the recommended route including theinterruption-predicted section from among the candidate routes, based onthe interruption-predicting information acquired by theinterruption-predicting information acquisition code; and a step of,displaying information based on the recommended route on a display oroutputting audio information based on the recommended route to aspeaker, wherein the recommended-route selecting code acquires, for eachof the candidate routes, a required time necessary for the vehicle totravel on the candidate route, calculates a decision value obtained byadding an additional value based on the interruption-predictinginformation to the required time for each of the candidate routes, andcompares the decision values of the respective candidate routes toselect the recommended route.
 19. A non-transitory computer readablemedium storing a computer program for searching for a recommended routefrom a departure point to a destination including an automated drivingsection where automated driving control of a vehicle is performed, thecomputer program comprising: route candidate acquisition code foracquiring a plurality of candidate routes that are candidates for therecommended route; interruption section specifying code, for each of thecandidate routes acquired by the route candidate acquisition code,specifying an interruption section where automated driving control isinterrupted in the automated driving section included in the candidateroute; interruption information acquisition code, based on theinterruption section specified by the interruption section specifyingcode, for each of the candidate routes, acquiring interruptioninformation indicating that the automated driving control is interruptedin the automated driving section included in the candidate route;recommended-route selecting code for selecting the recommended routeincluding the interruption section from among the candidate routes,based on the interruption information acquired by the interruptioninformation acquisition code; and a display that displays informationbased on the recommended route or a speaker that outputs audioinformation based on the recommended route, wherein therecommended-route selecting code acquires, for each of the candidateroutes, a required time necessary for the vehicle to travel on thecandidate route, calculates a decision value obtained by adding anadditional value based on the interruption information to the requiredtime for each of the candidate routes, and compares the decision valuesof the respective candidate routes to select the recommended route. 20.A non-transitory computer readable program for storing computer programfor searching for a recommended route from a departure point to adestination including an automated driving section where automateddriving control of a vehicle is performed, the computer programcomprising: route candidate acquisition code for acquiring a pluralityof candidate routes that are candidates for the recommended route;interruption-predicted section specifying code, for each of thecandidate routes acquired by the route candidate acquisition code,specifying an interruption-predicted section where there is apossibility that automated driving control will be interrupted in theautomated driving section included in the candidate route;interruption-predicting information acquisition code, based on theinterruption-predicted section specified by the interruption-predictedsection specifying code, for each of the candidate routes, acquiringinterruption-predicting information indicating that the automateddriving control is predicted to be interrupted in the automated drivingsection included in the candidate route; recommended-route selectingcode for selecting the recommended route including theinterruption-predicted section from among the candidate routes, based onthe interruption-predicting information acquired by theinterruption-predicting information acquisition code; and a display thatdisplays information based on the recommended route or a speaker thatoutputs audio information based on the recommended route, wherein therecommended-route selecting code acquires, for each of the candidateroutes, a required time necessary for the vehicle to travel on thecandidate route, calculates a decision value obtained by adding anadditional value based on the interruption-predicting information to therequired time for each of the candidate routes, and compares thedecision values of the respective candidate routes to select therecommended route.